SPLIT-SYSTEM HEAT PUMP December 2019 No. OCH640 REVISED EDITION-D SERVICE MANUAL Indoor unit [Model Name] [Service Ref.] Revision: • Some descriptions have been modified in REVISED EDITION-D. PLA-A12EA7 PLA-A18EA7 PLA-A24EA7 PLA-A30EA7 PLA-A36EA7 PLA-A42EA7 PLA-A12EA7 PLA-A18EA7 PLA-A24EA7 PLA-A30EA7 PLA-A36EA7 PLA-A42EA7 Grille model [Model Name] OCH640 REVISED EDITION-C is void.
1 REFERENCE MANUAL OUTDOOR UNIT SERVICE MANUAL Model Name Service Ref. Service Manual No.
2 SAFETY PRECAUTION 2-1. ALWAYS OBSERVE FOR SAFETY Before obtaining access to terminal, all supply circuits must be disconnected. 2-2. CAUTIONS RELATED TO NEW REFRIGERANT Cautions for units utilising refrigerant R410A Use the following tools specifically designed for use with R410A refrigerant. Use new refrigerant pipes. The following tools are necessary to use R410A refrigerant.
[1] Cautions for service (1) Perform service after recovering the refrigerant left in the unit completely. (2) Do not release refrigerant in the air. (3) After completing service, charge the cycle with specified amount of refrigerant. (4) When performing service, install a filter drier simultaneously. Be sure to use a filter drier for new refrigerant. [2] Additional refrigerant charge When charging directly from cylinder (1) Check that cylinder for R410A on the market is a syphon type.
3 PARTS NAMES AND FUNCTIONS 3-1.
3-2. Wired Remote Controller Controller interface The functions of the function buttons change depending on the screen. Refer to the button function guide that appears at the bottom of the LCD for the functions they serve on a given screen. When the system is centrally controlled, the button function guide that corresponds to the locked button will not appear. Main display Main menu Fri Room MENU RETURN SELECT HOLD ON OFF 83 Cool Set temp. Auto Mode Temp.
Display The main display can be displayed in two different modes: “Full” and “Basic”. The initial setting is “Full”. To switch to the “Basic” mode, change the setting on the Main display setting. (Refer to operation manual included with remote controller.) All icons are displayed for explanation. 2 345 6 7 $ Fri # 6 7 8 9 0 1 1 Room 83 1 Auto 83 Mode Fri # 3 9 @ ) Set temp. Cool Cool 4 Temp. 2 $ 8 Mode Fan Set temp. 83 2 ! 3 Auto Temp.
Main menu Press the MENU button. Move the cursor to the desired item with the F1 and F2 buttons, and press the SELECT button. Operation Vane · Louver · Vent. (Lossnay) High power Comfort Manual vane angle 3D i-See sensor Timer menu Timer ON/OFF timer Auto-OFF timer Weekly timer OU silent mode Energy saving Restriction Temp.
Continue from the previous page. Maintenance menu Error information Filter information Cleaning Auto descending panel Descending operation Descending adjustment Service menu Test run menu Test run Drain pump test run Maintenance information Model name input Serial No. input Dealer information input Initialize maintenance info.
Main menu list Main menu Setting and display items Operation Vane · Louver · Vent. (Lossnay) Use to reach the comfortable room temperature quickly. • Units can be operated in the High-power mode for up to 30 minutes. Comfort Manual vane angle Use to fix each vane angle. Timer Use to set the following functions for 3D i-See sensor. • Air distribution • Energy saving option • Seasonal airflow ON/OFF timer *1 Use to set the operation ON/OFF times. • Time can be set in 5-minute increments.
Main menu Initial setting Setting and display items Basic setting Setting details Main/Sub When connecting 2 remote controllers, one of them needs to be designated as a sub controller. Clock Use to set the current time. Daylight saving time Set the daylight saving time. Administrator The administrator password is required to make the settings for the following password items.
3-3. IR wireless remote controller (Option) CHECK TEST RUN display CHECK and TEST RUN display indicate that the unit is being checked or test-run. MODEL SELECT display Blinks when model is selected. display Lights up while the signal is transmitted to the indoor unit when the button is pressed. display SET TEMP. display indicates the desired temperature which is set. CLOCK display display Displays the current time.
4 SPECIFICATIONS Service Ref. Power supply (phase, cycle, voltage) Max. Fuse Size Min Circuit Ampacity PLA-A12EA7 Single phase, 60 Hz, 208/230 V 15 1 PLP-40EAEU: Munsell 6.4Y 8.9/0.4 PLP-41EAEU: Munsell 1.0Y 9.2/0.2 Plate fin coil Turbo fan (direct) × 1 0.05 0.
Service Ref. Power supply (phase, cycle, voltage) Max. Fuse Size Min Circuit Ampacity PLA-A30EA7 A A INDOOR UNIT External finish (Panel) Heat exchanger Fan Fan (drive) × No. Fan motor output Fan motor Airflow (Low-Medium2-Medium1-High) External static pressure Booster heater Operation control & Thermostat Noise level (Low-Medium2-Medium1-High) Field drain pipe O.D. Dimensions W D H Weight kW F.L.A. CFM (m³/min) Pa (mmAq) kW dB inch (mm) inch (mm) inch (mm) inch (mm) lb (kg) Service Ref.
5 NOISE CRITERION CURVES PLA-A12EA7 NOTCH SPL(dB) High 30 Medium1 29 Medium2 28 Low 27 LINE PLA-A18EA7 90 bar) NC-70 60 NC-60 50 NC-50 40 NC-40 30 NC-30 20 APPROXIMATE THRESHOLD OF HEARING FOR CONTINUOUS NOISE 63 125 OCTAVE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 bar) OCTAVE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.
PLA-A36EA7 NOTCH SPL(dB) High 44 Medium1 41 Medium2 37 Low 32 PLA-A42EA7 LINE bar) 80 70 NC-70 60 NC-60 50 NC-50 40 NC-40 30 NC-30 20 10 LINE 90 OCTAVE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 OCTAVE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.
6 OUTLINES AND DIMENSIONS PLA-A12EA7 PLA-A30EA7 OCH640D PLA-A18EA7 PLA-A36EA7 PLA-A24EA7 PLA-A42EA7 17 Unit: inch (mm)
7 WIRING DIAGRAM PLA-A12EA7 PLA-A30EA7 OCH640D PLA-A18EA7 PLA-A36EA7 PLA-A24EA7 PLA-A42EA7 18
8 REFRIGERANT SYSTEM DIAGRAM PLA-A12EA7 PLA-A30EA7 PLA-A18EA7 PLA-A36EA7 PLA-A24EA7 PLA-A42EA7 Strainer (#50) Heat exchanger Refrigerant GAS pipe connection (Flare) Condenser/evaporator temperature thermistor (TH5) Refrigerant flow in cooling Refrigerant flow in heating Room temperature thermistor (TH1) OCH640D Refrigerant LIQUID pipe connection (Flare) Pipe temperature thermistor/liquid (TH2) Distributor with strainer (#50) Strainer (#50) 19
9 TROUBLESHOOTING 9-1. TROUBLESHOOTING Present and past check codes are logged, and they can be displayed on the wired remote controller and control board of outdoor unit. Actions to be taken for service, which depends on whether or not the trouble is reoccurring in the field, are summarized in the table below. Check the contents below before investigating details.
9-2. MALFUNCTION-DIAGNOSIS METHOD BY REMOTE CONTROLLER When a malfunction occurs to air conditioner, both indoor unit and outdoor unit will stop and operation lamp blinks to inform unusual stop.
• Refer to the following tables for details on the check codes. [Output pattern A] Beeper sounds OPERATION INDICATOR lamp blink pattern Beep Self-check starts (Start signal received) Beep Off Approx. 2.5 s Beep Beep 1st 2 nd 3 rd On 0.5 s On 0.5 s On 0.5 s Beep Beep nth 1st On 0.5 s Off Approx. 2.5 s Number of blinks/beeps in pattern indicates the check code in the following table (i.e., n=5 for “P5”) On 0.5 s Beep 2 nd · · · Repeated On 0.
• On IR wireless remote controller The continuous buzzer sounds from receiving section of indoor unit. Blink of operation lamp • On wired remote controller 1 Check code displayed in the LCD. (Refer to the previous page, 1 check code.) • If the unit cannot be operated properly after the test run, refer to the following table to find out the cause.
9-3. SELF-DIAGNOSIS ACTION TABLE Check code P1 Note: Errors to be detected in outdoor unit, such as codes starting with F, U or E (excluding E0 to E7), are not covered in this document. Please refer to the outdoor unit service manual for the details. Abnormal point and detection method Cause Countermeasure Room temperature thermistor (TH1) 1 The unit is in 3-minute resume prevention mode if short/open of thermistor is detected. Abnormal if the unit does not reset normally after 3 minutes.
Check code P6 Abnormal point and detection method Cause Freezing/overheating protection is working 1 Freezing protection (Cooling mode) • In case when outside temperature > −4°F [−20:] The unit is in 6-minute resume prevention mode if pipe temperature stays under −5°F [−15:] for 3 minutes, 3 minutes after the compressor started. Abnormal if it stays under −5°F [−15:] for 3 minutes again within 16 minutes after 6-minute resume prevention mode.
Check code Abnormal point and detection method P9 Condenser/evaporator temperature thermistor (TH5) 1 The unit is in 3-minute resume protection mode if short/open of thermistor is detected. Abnormal if the unit does not get back to normal within 3 minutes. (The unit returns to normal operation, if it has been reset normally.
Check code Abnormal point and detection method Cause E3 or E5 Remote controller transmission error(E3)/signal receiving error(E5) 1 Abnormal if remote controller could not find blank of transmission path for 6 seconds and could not transmit. (Check code: E3) 2 Remote controller receives transmitted data at the same time and compares the received and transmitted data. Abnormal if these data are judged to be different 30 continuous times.
9-4. TROUBLESHOOTING BY INFERIOR PHENOMENA Note: Refer to the manual of outdoor unit for the detail of remote controller. Phenomena Cause Countermeasure (1)Upward/downward vane performance failure 1 The vane is not downward during defrost1 Normal operation (The vane is set to horiing and heat preparation and when the zontal regardless of remote control.) thermostat is OFF in HEAT mode. (Working of COOL protection function) 2 Check 2 (left). • Check the vane motor. (Refer to "9-6.
9-5. EMERGENCY OPERATION 9-5-1. When IR wireless remote controller troubles or its battery is exhausted When the remote controller cannot be used When the batteries of the remote controller run out or the remote controller malfunctions, the emergency operation can be done using the emergency buttons on the grille. Starting operation for more than 2 button • To operate the cooling mode, press the seconds. for more than 2 button • To operate the heating mode, press the seconds.
9-6. HOW TO CHECK THE PARTS PLA-A12EA7 PLA-A18EA7 PLA-A30EA7 PLA-A36EA7 Parts name Room temperature thermistor (TH1) Pipe temperature thermistor/liquid(TH2) Condenser/Evaporator temperature thermistor (TH5) Vane motor (MV) White PLA-A24EA7 PLA-A42EA7 Check points Disconnect the connector then measure the resistance with a tester. (At the ambient temperature of 50 to 86˚F [10 to 30˚C]) Refer to “9-6-1. Thermistor”. Measure the resistance between the terminals with a tester.
9-6-1. Thermistor Thermistor for lower temperature Room temperature thermistor(TH1) Pipe temperature thermistor/liquid(TH2) Condenser/evaporator temperature thermistor(TH5) 50 40 t(:)Rt=15exp { 3480( 1 273+t 1 )} 273 1 T(˚F)Rt=15exp { 3480( 273+ T-32 1.8 32˚F 50˚F 68˚F 77˚F 86˚F 104˚F [0:] [10:] [20:] [25:] [30:] [40:] Resistance (k") Thermistor R0=15 k" ± 3% Fixed number of B=3480 ± 2% 1 )} 273 15 k" 9.6 k" 6.3 k" 5.
9-7. TEST POINT DIAGRAM Indoor controller board PLA-A12EA7 PLA-A30EA7 PLA-A18EA7 PLA-A36EA7 TB5 Connect to wired remote controller 10.4–14.6 V DC PLA-A24EA7 PLA-A42EA7 CN5Y i-See sensor motor (MT) 12 V pulse output CNV Vane motor (MV) 12 V pulse output SW1 Model selection CN90 Connect to the wireless remote controller board (CNB) J41, J42 Jumper wire (Pair No.
9-8. FUNCTIONS OF DIP SWITCH AND JUMPER WIRE Each function is controlled by the DIP switch and the jumper wire on indoor controller board. PLA-A12EA7 PLA-A30EA7 Jumper wire Functions SW1 Model settings PLA-A18EA7 PLA-A36EA7 Setting by the DIP switch and jumper wire MODEL PLA-A·EA7 MODEL SW2 Capacity settings PLA-A12EA7 PLA-A18EA7 PLA-A24EA7 J41 J42 Pair number setting with IR wireless remote controller OCH640D PLA-A24EA7 PLA-A42EA7 The black square (■) indicates a switch position.
10 FUNCTION SETTING 10-1. UNIT FUNCTION SETTING BY THE REMOTE CONTROLLER Each function can be set as necessary using the remote controller. The setting of function for each unit can only be done by the remote controller. (1) Functions available when setting the unit number to 00 Refer to the service manual that comes with each outdoor unit. (2) Functions available when setting the unit number to 01–03 or AL (07 in case of wireless remote controller) Function Filter sign Fan speed No.
11 SPECIAL FUNCTION 11-1. ROTATION FUNCTION (AND BACK-UP FUNCTION, 2ND STAGE CUT-IN FUNCTION) 11-1-1. Operation (1) Rotation function (and Back-up function) Outline of functions • Main and sub unit operate alternately according to the interval of rotation setting. Note: Main and sub unit should be set by refrigerant address. (Outdoor DIP switch setting) Refrigerant address "00" Main unit Refrigerant address "01" Sub unit • When error occurs to one unit, another unit will start operation.
• System constraint · This function is available only in cooling mode. Ex.) Set temp. by R/C = 68°F [20:] Set point = 79°F [26:] When request code number is “323”. 79°F [26:] Start operation 2nd unit Cut-in 7.2°F [4:] 2nd unit Cut-out 71.5°F [22:] [2nd stage cut-in function]··· Request code number "322–324" Main unit IC-1 Sub unit IC-2 Room temp. ] Set point Sub unit start operation Run Stop Run 68°F [20:] 11-1-2.
(2) How to send a request code Press the [ Main ] button. Main menu Select "Service" with the F2 and F3 and press the [SELECT] button. Service F1 F2 F3 MENU RETURN SELECT HOLD F4 ON OFF Enter the current maintenance password (4 numerical digits). Service menu Enter maintenance password 9999 Select: SELECT Cursor Service menu Test run Input maintenance info.
11-2. BACK-UP HEATING FUNCTION 11-2-1. Operation The back-up heater turns ON when both of the following conditions have been satisfied: A) When the room temperature has not risen after the heater ON delay time has passed. Note: The heater ON delay time starts when the condition of “set temperature − room temperature > 1°F [0.5:]” has been satisfied. B) Set temperature − room temperature ] 3°F [1.
12 DISASSEMBLY PROCEDURE PLA-A12EA7 PLA-A30EA7 PLA-A18EA7 PLA-A36EA7 PLA-A24EA7 PLA-A42EA7 OPERATING PROCEDURE 1. Removing the filter (1) Slide the knob of air intake grille toward the arrow to open the air intake grille. (See Figure 1.) (2) Pull down the lever of the air intake grille to remove the Figure 1 Be careful when removing heavy parts. PHOTOS/FIGURES Air intake grille Knob Grille filter. (See Figure 2.) 2.
OPERATING PROCEDURE 4. Removing the room temperature thermistor (TH1) (1) Remove the electrical box cover. (See Photo 1 and 2.) (2) Disconnect the connector CN20 (Red) from the indoor controller board. (3) Remove the room temperature thermistor with its holder. (See Photo 3.) Photo 3 Electrical box PHOTOS/FIGURES Thermistor (TH1) Indoor controller board CN20 Electrical box fixing screw (M5×10) Electrical box fixing screw (M5×10) Thermistor (TH1) Thermistor holder 5.
Be careful when removing heavy parts. OPERATING PROCEDURE 6. Removing the electrical box (1) Remove the electrical box cover (See Photo 1 and 2.) and the connectors (Refer to procedure 5.). (2) Remove the electrical box fixing screws (M5 × 10: 2 screws). (See Photo 3.) • Terminal block for earth and reactor • Indoor controller board • Thermistor (TH) (3) Remove the electrical box (2 hooks).
OPERATING PROCEDURE 8. Removing the fan motor (MF) (1) Remove the turbo fan. (See Photo 6 and refer to procedure 7.) (2) Remove the lead cover (tapping screw 4×10: 2 screws). (See Photo 9.) (3) Loosen the 2 clamps. (4) Remove the 3 washer nuts (M5). (5) Remove the fan motor. (6) Remove the 3 rubber mounts.
OPERATING PROCEDURE 10. Removing the drain pan (1) Remove the electrical box. (See photo 3 and refer to 6.) (2) Remove the bell mouth (tapping screw 4×10 : 2 screws). (See Photo 5.) (3) Remove the drain pan (screw M5×10: 4 screws). Photo 12 PHOTOS/FIGURES Drain pan Drain pan fixing screws 11. Removing the pipe temperature thermistor/liquid (TH2) Photo 13 and the condenser/evaporator temperature thermistor (TH5) (1) Remove the drain pan (Refer to procedure 10.
OPERATING PROCEDURE 12. Removing the drain pump (DP) (1) Remove the drain pan. (Refer to procedure 10.) (2) Cut the hose band and remove the hose. (3) Loosen the clamp of the drain pump. (4) Remove the drain pump (tapping screw 4×10: 2 screws/2 hooks). Photo 14 PHOTOS/FIGURES Drain pump Float switch Clamp Drain pump base fixing screws 13. Removing the float switch (FS) (1) Remove the drain pan. (Refer to procedure 10.) (2) Loosen the clamp of the drain pump. (See Photo 14.
OPERATING PROCEDURE 14. Removing the heat exchanger (1) Remove the drain pan. (Refer to procedure 10.) (2) Remove the piping cover (tapping screw 4×10: 3 screws). (3) Remove the coil plate (tapping screw 4×10: 2 screws). (4) Remove the heat exchanger fixing screws (tapping screw 4×10: 2 screws). (5) Remove the coil support (tapping screw 4×10: 1 screw each) PHOTOS/FIGURES Photo 16 Coil support fixing screw Heat exchanger fixing screws Coil support ■ PLA-A12/18EA7: 1 coil support (See photo16.
HEAD OFFICE: TOKYO BUILDING, 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN CCopyright 2016 MITSUBISHI ELECTRIC CORPORATION Issued: Dec. 2019 No.OCH640 REVISED EDITION-D Issued: Sep. 2018 No.OCH640 REVISED EDITION-C Issued: May 2018 No.OCH640 REVISED EDITION-B Issued: Mar. 2018 No.OCH640 REVISED EDITION-A Published: Oct. 2016 No.OCH640 Made in Japan Specifications are subject to change without notice.
